Search

A comprehensive mechanistic investigation was conducted on the coupling reaction of aryl sulfoxides with phenols by using trifluoroacetic anhydride to yield biaryls. NMR experiments revealed that our previously proposed mechanism, which consists of a cascade of an interrupted Pummerer reaction and a rate‐determining [3,3] sigmatropic rearrangement, is reasonable. The electronic effects of the substrates were also evaluated to elucidate the nature of the rearrangement step. Based on experimental observations and theoretical calculations, we conclude that the rearrangement is highly asynchronous and stepwise rather than concerted when electron‐rich phenols are employed for the reaction. [ABSTRACT FROM AUTHOR]

Sulfinyl‐directed peri‐selective C−H fluoroalkoxylation of aryl sulfoxides with fluorinated alcohols has been developed. By means of a palladium catalyst and PhI(OAc)2 as an oxidant, a range of fluoroalkoxy groups can be installed onto the peri position of aryl sulfoxides. The remaining sulfinyl groups on the fluoroalkoxylation products further promote Pummerer‐based C−H functionalizations. [ABSTRACT FROM AUTHOR]

An unprecedented S−N variant of the benzidine rearrangement for construction of biaryls has been developed. Aryl sulfoxides underwent dehydrogenative coupling with anilines by successive treatment with trifluoromethanesulfonic anhydride and trifluoromethanesulfonic acid to provide the corresponding 2‐amino‐2′‐sulfanyl‐ and/or 4‐amino‐4′‐sulfanylbiphenyls. Mechanistic studies indicate that the C−C‐bond‐forming sigmatropic rearrangement proceeds intramolecularly from dicationic S−N‐tethered species. [ABSTRACT FROM AUTHOR]

Sulfoxide-promoted ortho -C–H functionalization reactions of aromatic compounds have emerged as powerful tools for organic synthesis. Among them, [3,3] sigmatropic rearrangement induced by interrupted Pummerer reaction or electrophilic activation of sulfoxides has proved to be a fruitful strategy due to its versatility and high reaction efficiency. This digest paper mainly focuses on recent progress on C–H functionalization reactions of aryl sulfoxides via [3,3] sigmatropic rearrangement of sulfonium-tethered intermediates. [ABSTRACT FROM AUTHOR]

Sonogashira-Hagihara-type alkynylation of diaryl sulfoxides with unactivated terminal alkynes has been developed. With a combination of a palladium-NHC catalyst and LiOtBu as a base, a series of diaryl sulfoxides were converted into the alkynylated products via C-S bond cleavage. [ABSTRACT FROM AUTHOR]

Treatment of aryl sulfoxides and sulfonanilides with trifluoroacetic anhydride resulted in the dehydrative metal-free construction of the corresponding unsymmetrical biaryls. The reaction would proceed via (1) the activation of aryl sulfoxide with the anhydride, (2) interrupted Pummerer reaction of the resulting arylsulfonium with sulfonanilide, (3) [3,3] sigmatropic rearrangement to cleave the transient S–N bond and to form the prospective biaryl C–C bond, and (4) global aromatization. The choice of the amino protecting group is crucial, and only N -sulfonylanilines, i.e., sulfonanilides, could participate in the formation of biaryls. Image 1 [ABSTRACT FROM AUTHOR]

Abstract: Aryl sulfoxides have been identified as a class of organic compounds capable of inducing DNA cleavage in the presence of UV light. Phenyl sulfoxide and methyl phenyl sulfoxide were both shown to cleave pBR322 DNA at concentrations of 180 and 360μM, respectively. Radical trapping studies indicate carbon-centered radicals are the active cleavage species. [Copyright &y& Elsevier]

Aryl sulfoxides underwent dehydrogenative coupling with unprotected anilines under Pummerer-type conditions to provide the corresponding 2-amino-2'-sulfanyl-and/or 4-amino-4'-sulfanylbiphenyls. Aryl sulfoxides underwent dehydrogenative coupling with unprotected anilines under Pummerer-type conditions to provide the corresponding 2-amino-2'-sulfanyl-and/or 4-amino-4'-sulfanylbiphenyls. [Extracted from the article]